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Abstract:

An armature core includes a core portion formed of a lamination of plural
noncrystalline metallic foil bands and resin for bond-fixing the
non-crystalline metallic foil bands, wherein the armature core is
provided with at least two cut surfaces with respect to the lamination
layers. Amorphous metal is used as the iron base of the non-crystalline
metallic foil bands. The cut surfaces are perpendicular to the
lamination-layers of the non-crystalline foil bands. For the amorphous
core, a resin mold is formed. The contact portions between winding wires
and amorphous are provided with edge roundness. Further, an axial gap
motor using cut cores of amorphous lamination as stator cores is
provided. Still further, the stator includes: a plurality of stator cores
in a bar shape, the stator cores being disposed along circumferential
direction, wherein the axial line of the rotor shaft is the central axis
of the circumferential direction, and wherein an axial direction of the
stator cores is along the axial line direction AX of the rotor shaft; a
stator core holding member in a disc form, the stator having a plurality
of holes or recessions that are substantially in the same shape as a
cross-sectional shape of the stator cores and are arranged along the
circumferential direction, wherein the axial line of the rotor shaft is
the central axis of the circumferential direction; and coils wound around
the stator cores, and wherein the stator cores are inserted in the holes
or recessions of the stator core holding member and held by fixing in
vicinities of respective central portions thereof, the central portions
being with respect to the axial direction thereof.

Claims:

1. An armature core for an electrical rotating machine, comprising:a core
portion including a plurality of non-crystalline metallic foil bands
laminated; andresin for bond-fixing the non-crystalline metallic foil
bands,wherein at least two cut surfaces are formed on lamination layers
of the non-crystalline metallic foil bands.

2. The armature core of claim 1, wherein amorphous metal is used as an
iron base of the non-crystalline metallic foil bands.

3. The armature core of claim 1, wherein the cut surfaces are
perpendicular to surfaces of the laminated non-crystalline metallic foil
bands.

4. The armature core of claim 1, wherein, when the armature core is to be
used in a motor, a portion of the resin on a gap side of the armature
core has a thickness of 0.3 mm-0.5 mm.

9. The armature core of claim 8, wherein the core portion is exposed at
the recession of the resin layer.

10. An axial gap motor, comprising:a stator that includes a plurality of
stator cores, extending along an axial direction, disposed along a
circumferential direction, and winding wires wound around the respective
stator cores; anda rotor including magnets facing the amorphous
cores,wherein cut cores including an amorphous lamination are used as the
stator cores.

11. An axial gap electrical rotating machine, comprising:a stator;
androtors that are disposed along an axial line direction of a rotor
shaft, the rotors sandwiching and facing the stator therebetween with
predetermined gaps,wherein the stator comprises:a plurality of stator
cores in a bar shape, the stator cores being disposed along a
circumferential direction around a central axis of the circumferential
direction on the axial line of the rotor shaft, and wherein an axial
direction of the stator cores is along the axial line direction of the
rotor shaft;a stator core holding member in a disc form having a
plurality of holes or recessions that are substantially in the same shape
as a cross-sectional shape of the stator cores and are disposed along the
circumferential direction, wherein the axial line of the rotor shaft is
the central axis of the circumferential direction; andcoils wound around
the stator cores,and wherein the stator cores are inserted in the holes
or recessions of the stator core holding member and held by fixing in
vicinities of respective central portions thereof, the central portions
being around the axial direction thereof.

12. The axial gap electrical rotating machine of claim 11, wherein the
stator cores are fixed to the holes or recessions of the stator core
holding member by any one of press-inserting, shrink fitting, and gap
fitting.

13. The axial gap electrical rotating machine of claim 11, wherein the
stator core holding member is fixed to a housing having a cylindrical
shape or the same inner circumferential shape as a shape of an outer
circumferential edge of the stator core holding member.

14. The axial gap electrical rotating machine of claim 13, wherein the
stator core holding member is fixed to the inner circumferential surface
of the housing by any one of press-inserting, shrink fitting, and gap
fitting.

15. The axial gap electrical rotating machine of claims 11, wherein the
stator core holding member and a bearing holding member disposed on an
inner side, with respect to a radial direction, of the stator core
holding member are integrally formed with each other.

16. The axial gap electrical rotating machine of claim 11,wherein the
stator core holding member is formed of a conductive metallic material
with a high strength and has notches along a radial direction, the
notches extending from an outer circumferential edge thereof to the holes
or recessions,and wherein the outer circumferential edge divided by the
notches along the circumferential direction CIR is formed with a first
outer circumferential edge portion in contact with an inner
circumferential surface of a housing in a cylindrical shape for housing
the stator and rotors, and a second outer circumferential edge portion
forming a gap from the inner circumferential surface of the housing.

17. The axial gap electrical rotating machine of claim 16, wherein at
least either an edge portion of the hole or recession of the stator core
holding Member fixing and holding the stator Cores, or the stator cores
is coated for electrical insulation to prevent a flow of a current
between the stator core holding member and the stator cores.

18. The axial gap electrical rotating machine of claim 11, wherein, for a
single stator pole, coils are arranged on both sides, in an axial
direction, of each stator core.

19. The axial gap electrical rotating machine of claim 11,wherein the
rotor disposed at a position being sandwiched by the stators has a field
magnetic pole holding member for holding permanent magnets that form a
field magnetic pole such that both sides, in the axial line direction. AX
of the rotor shaft, of the permanent magnets are exposed,and wherein the
rotor has no back yoke portion.

20. The axial gap electrical rotating machine of claim 12, wherein the
field magnetic pole holding member comprises two disc formed members that
hold the permanent magnets by sandwiching the permanent magnets in the
axial line direction AX of the rotor shaft.

Description:

CROSS REFERENCES TO RELATED APPLICATIONS

[0001]This application claims the foreign priority benefit under Title 35,
United States Code, §119(a)-(d) of Japanese Patent Application No.
2008-287268, filed on Nov. 10, 2008 in the Japan Patent Office, and
Japanese Patent Application No. 2009-088575, filed on Mar. 31, 2009 in
Japan Patent Office, the disclosure of which is herein incorporated by
reference in its entirety.

[0005]In recent years, electrical rotating machines with high efficiency
and low cost are in demand in view of fuel shortage, environmental
contamination, and economy. Amorphous metal is considered to be used for
such electrical rotational machines. Being materials excellent in
magnetic and mechanical properties including low loss, high magnetic
permeability, high strength and rust resistance, amorphous metals are
expected for motor cores in application to high efficiency and low cost
of a motor.

[0006]A commonly used amorphous metal is in a thin and continuous ribbon
form having a constant width. With regard to manufacturing methods of a
core from an amorphous metal in a ribbon form, related arts can be
roughly categorized into three methods. A first method uses a lamination
of wound ring forms of the amorphous metal as a core. For example, in
Patent Document 1, an example is described where a magnetic body made by
winding a continuous amorphous metallic ribbon, cutting it, and then
forming is used as a core. Herein, because the wound core is used as it
is, a loop circuit is formed with respect to current flowing, which
causes a large eddy current loss.

[0007]Further, there is nothing that protects the outer side of a core,
which makes it difficult to arrange winding wires.

[0008]Still further, as a member for insertion to be applied between cores
for fixing the cores is necessary, there is a problem of a complicated
manufacturing process.

[0009]As a second method, a part cut from a body formed by winding
amorphous metal is used as a core. For example, in Patent Document 2, a
core made by winding an amorphous thin body is held at the outer
circumference thereof by a shape maintaining material, such as a silicon
steel plate, and attached to a forming jig for forming. In this state,
heat treatment and annealing treatment are performed. Thereafter, the
silicon steel plate is removed, and then, cut and after cutting, an
adhesive agent is coated on the cut surface. By this method, because not
all of the winding core can be cut, there is a problem of a low
utilization ratio, and it is also highly possible that rust is caused
through cutting. Further, there is a problem that the shape and
dimensions of a core cannot be easily designed.

[0010]As a third method, a core is manufactured by coating an adhesive
agent on small pieces of amorphous metal, laminating the plurality of
amorphous small pieces, and heat-press-bonding the lamination. As an
example, a technology for manufacturing amorphous lamination material is
described in Patent Document 3. However, coating an adhesive agent causes
a problem of lowering the volume ratio of the core.

[0011]The basic structure of a permanent-magnet-synchronization electrical
rotating machine is configured with a soft magnetic material, coils, and
permanent magnets. The losses of such an electrical rotating machine can
be roughly categorized into iron loss and copper loss. The iron loss is
determined by the properties of a soft magnetic material. The copper loss
is determined by the resistance value of the coil, in other words, by the
volume ratio, wherein the more compact the structure of the winding is,
the smaller the loss is. A method of increasing the efficiency can be
attained by a design of the shape, dimensions and the like of an
electrical rotating machine, which makes these losses to be low, however,
a change in the properties of the material also contributes to high
efficiency.

[0012]Employment of an axial gap electrical rotating machine is considered
to be one of methods for decreasing the loss of a flat electrical
rotating machine structure. A stator used for a radial electrical
rotating machine which is flat and thin in the axis direction of the
rotor shaft is in most cases given with a structure having a winding wire
around a core part that is formed by punching electromagnetic steel
plates and laminating the punched plates along the axial direction of a
rotor shaft. However, because the ratio of the coil end portion of the
coil becomes large with respect to the core part facing the rotor and
being effective for torque output, the coil resistance value becomes
large, which increases the copper loss. Accordingly, for the structure of
flat electrical rotating machines, axial types in which the surfaces, of
the core portions, contributable to the torque output and facing the
rotors are arranged along the axial direction of the rotor shaft are
effective for reducing the copper loss. Further, for the core portions,
it is desirable to adopt a material with a high magnetic permeability and
low iron loss in order to reduce the iron loss.

[0013]One basic structure of an axial gap electrical rotating machine is
disclosed by Patent Document 4. Having a teeth portion and yoke portion,
this structure has facing surfaces contributable to torque output only on
one side with respect to the rotor axis direction. Further, because a
magnetic flux flows from the teeth portion to the yoke portion in this
structure, it is necessary to use a soft magnetic material for which a
consideration is made so that a magnetic flux flows in the yoke portion
three dimensionally. In order to satisfy these requirements, it is
necessary to use a material, such as a powder magnetic core, whose
magnetic characteristics has three dimensional isotropy, however, such a
material has lower magnetic permeability and larger iron loss than
commonly used silicon steel plates, causing a problem of difficulty with
downsizing in obtaining an electrical rotating machine with a high
output.

[0014]As a solution for solving the above-described problems, there is
proposed a technology for an electric rotating machine described in
Patent Document 5. With the electrical rotating machine described in
Patent Document 2, an example is disclosed where a stator is provided
with two surfaces in the axis direction of the rotor shaft, the surfaces
facing rotors, and cores are structured with silicon steel plates. A
method is disclosed in which, after a wire is wound around cores, and the
cores are fixed by molding with a resin member to form a stator.

[0016]An amorphous metal is contributable to the high efficiency of a
motor because of the characteristics in energy saving and high magnetic
permeability. As an amorphous metal is thin, hard, and fragile, the
amorphous metal is difficult to be subjected to processing, such as
punching-out or cutting, and has the problems that an optimal shape
applicable to a motor cannot be formed by the technologies described as
the related arts and that the manufacturing process becomes complicated.

[0017]Further, a method that performs mold-fixing with engineering plastic
or the like, such as a thermoset resin, is conventionally used for an
electrical rotating machine, however, the application of the method is
limited to electrical rotating machines of a small capacity. It was
difficult in terms of strength to apply a mold-fixing method to
electrical rotating machines with requirement for a large toque or high
rotational speed.

SUMMARY OF THE INVENTION

[0018]In an aspect of the invention, amorphous cores usable for an
electrical rotating machine are provided.

[0019]Further, in an aspect of the invention, an axial gap motor using
these amorphous cores is provided.

[0020]Further, in an aspect of the invention, there is provided an axial
gap electrical rotating machine in a small size and with a high
efficiency, wherein the axial gap electrical rotating machine satisfies
the requirement of both downsizing and core-holding high-strength for an
axial gap electrical rotating machine.

[0021]Further, in an aspect of the invention, an armature core used for an
electrical rotating machine includes: a core portion having a lamination
of a plurality of non-crystalline metallic foil bands; and resin for
bond-fixing the non-crystalline metallic foil bands, wherein at least two
cut surfaces are formed with respect to lamination layers.

[0022]Further, in an aspect of the invention, an amorphous material is
used for the non-crystalline metallic foil bands.

[0023]Further, in an aspect of the invention, the cut surfaces are
perpendicular to the lamination layers of the non-crystalline metallic
foil bands.

[0024]Further, in an aspect of the invention, when the armature core is to
be used for a motor, a resin portion on a gap side of the armature core
has a thickness of 0.3 mm-0.5 mm.

[0025]Further, in an aspect of the invention, an armature core used for an
electrical rotating machine includes: a core portion having a lamination
of a plurality of non-crystalline metallic foil bands; and means for
bond-fixing the non-crystalline metallic foil bands.

[0026]Further, in an aspect of the invention, an armature core used for an
electrical rotating machine includes a core portion having a lamination
of a plurality of non-crystalline metallic foil bands, wherein the
non-crystalline metallic foil bands are connected between layers.

[0027]Further, in an aspect of the invention, an armature core used for an
electrical rotating machine includes: a core portion having a lamination
of a plurality of non-crystalline metallic foil bands; and a resin layer
arranged on an outermost side of the lamination layers.

[0028]Further, in an aspect of the invention, edge portions of the resin
layer are provided with an edge roundness of R.

[0029]Further, in an aspect of the invention, an armature core used for an
electrical rotating machine includes: a core portion having a lamination
of non-crystalline metallic foil bands in a ring form; and a resin layer
covering the core portion, wherein the resin layer is provided with a
recession.

[0030]Further, in an aspect of the invention, the core portion is exposed
at the recession of the resin layer.

[0031]Further, in an aspect of the invention, an axial gap motor includes:
a stator that has a plurality of stator cores extending along an axial
direction and being disposed along a circumferential direction, and
winding wires wound around the respective stator cores; and rotors having
magnets facing the amorphous cores, wherein cut cores having an amorphous
lamination are used as the stator cores.

[0032]Further, in an aspect of the invention, the magnets have a
substantial rhombic shape.

[0033]Further, in an aspect of the invention, the magnets have a skewed
shape.

[0034]Further, in an aspect of the invention, there is provided an axial
gap electrical rotating machine, wherein a stator includes: a plurality
of stator cores in a bar shape, the stator cores being disposed along a
circumferential direction, wherein the axial line of a rotor shaft is the
central axis of the circumferential direction, and wherein an axial
direction of the stator cores is along the axial line direction AX of the
rotor shaft; a stator core holding member in a disc form, the stator core
holding member having a plurality of holes or recessions that are
substantially in the same shape as the cross-sectional shape of the
stator cores and disposed along the circumferential direction, wherein
the axial line of the rotor shaft is the central axis of the
circumferential direction; and coils wound around the stator cores.
Herein, the stator cores are inserted in the holes or recessions of the
stator core holding member and held by fixing in vicinities of respective
central portions thereof, the central portions being around the axial
direction thereof.

[0035]Further, in an aspect of the invention, it is possible to fix stator
cores in the slot portions of the disc of a stator core holding member by
press-inserting or shrink fitting, thereby realizing fixing with strength
higher than the strength of fixing of stator cores by a conventional
mold.

[0036]Further, in an aspect of the invention, the stator core holding
member is formed of a conductive high strength metallic material and has
notches along a radial direction, the notches extending from an outer
circumferential edge thereof to the holes or recessions, and the outer
circumferential edge divided by the notches along the circumferential
direction is formed with a first outer circumferential edge portion in
contact with an inner circumferential surface of a housing in a
cylindrical shape for housing the stator and rotors, and a second outer
circumferential edge portion forming a gap from the inner circumferential
surface of the housing.

[0037]Further, in an aspect of the invention, in a case, for example,
where the stator core holding member can be fixed by press-inserting to a
housing in a cylindrical shape and is formed of a conductive material,
such as metal, because the stator core holding member has notches
extending, along the radial direction, from the outer circumferential
edge thereof to the holes or recessions, and the second outer
circumferential edge portion is not in contact with the housing, the
stator core holding member is in a shape in which an eddy current path
generated around the stator core holding member is partially cut off, and
thereby the iron loss can be reduced.

[0038]Further, in an aspect of the invention, in addition to the
above-described structures, there is further provided an axial gap
electrical rotating machine having more than one above-described stators
arranged along the axial direction of the rotor shaft.

[0039]Further, in an aspect of the invention, because the stator core
holding member can be fixed to the housing with a high strength and high
accuracy, there is provided an axial gap electrical rotating machine in
which a plurality of above-described stators can be disposed in a single
electrical rotating machine along the axial line direction of the rotor
shaft.

[0040]In an aspect of the invention, there are provided amorphous cores
applicable to an electrical rotating machine, enabling prevention of
peeling-off of the cores and prevention of corrosion of gap surfaces.

[0041]Further, in an aspect of the invention, because processing, of a cut
core, that allows changes in the shape and dimensions in applying an
amorphous metal to a motor is realized, improvement in the performance of
a motor using an amorphous core can be expected. Further, because the
forming process from a ribbon-formed amorphous metal to a cut core is
simple and allows reduction in the cost, it is possible to obtain an
economical motor.

[0042]Further, in an aspect of the invention, it is possible to provide a
thin-shaped and highly-efficient motor with an axial gap structure using
amorphous cores.

[0043]Further, in an aspect of the invention, it is possible to provide a
highly-efficient and small-sized axial gap electrical rotating machine
satisfying the requirement of both downsizing and core-holding
high-strength for an axial gap electrical rotating machine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0044]Objects and features of the invention will be clearer by the
detailed description below with reference to the attached drawings.

[0045]FIG. 1A shows an amorphous armature core related to one embodiment
in accordance with the invention;

[0046]FIG. 1B shows a cross-section in parallel to the gap surface in FIG.
1A of the amorphous armature core related to the one embodiment in
accordance with the invention;

[0047]FIG. 2 shows a mold forming device for the amorphous care related to
the one embodiment in the invention;

[0048]FIG. 3 shows a mold for the amorphous core related to the one
embodiment in accordance with the invention;

[0049]FIG. 4 shows amorphous cores in a ring-form related to the one
embodiment in accordance with the invention;

[0050]FIG. 5 shows an amorphous cut core related to the one embodiment in
accordance with the invention;

[0051]FIG. 6 shows an axial gap motor using the amorphous cores related to
the one embodiment in accordance with the invention;

[0052]FIG. 7 shows a position relationship between the Magnets and stator
cores of the axial gap motor related to the one embodiment in accordance
with the invention;

[0053]FIG. 8 shows the cogging torque waveform of the axial gap motor
related to the one embodiment in accordance with the invention;

[0055]FIG. 10 shows the detailed shape of a magnet in the one embodiment
in accordance with the invention;

[0056]FIG. 11 shows the detailed shape of an amorphous core in the one
embodiment in accordance with the invention;

[0057]FIG. 12 is a partial cross-sectional perspective view of an
electrical rotating machine in accordance with a third embodiment;

[0058]FIG. 13 is an exploded perspective view where component elements of
the electrical rotating machine in accordance with the third embodiment
are spread out along the rotor axis direction;

[0059]FIGS. 14A and 14B are structural views of a core holding member
constructing the stator of the electrical rotating machine in accordance
with the third embodiment, wherein diagram FIG. 14A is a perspective view
and FIG. 14B is a plan view;

[0060]FIGS. 15A to 15E illustrate a manufacturing method, shapes and the
like of stator cores used for the stator of the electrical rotating
machine in the third embodiment, wherein FIG. 15A is a perspective view
illustrating the shape of the wiring core of electromagnetic steel plates
before being cut into stator cores, FIG. 15B is a perspective view of a
stator core formed by cutting the winding core, FIG. 15C is a perspective
view of a stator core formed by powder compact forming from magnetic
powders, FIG. 15D is a perspective view of a stator core formed by powder
compact forming from magnetic powders, applying edge roundness at edge
portions; and FIG. 15E is a perspective view of a stator core with a
substantially rectangular cross-sectional shape;

[0061]FIG. 16 is a perspective view of a stator after fixing stator cores
to the core holding member constructing the stator;

[0062]FIG. 17 is an illustration of a method of fitting coils to the
stator cores;

[0063]FIG. 18 is an entire perspective view of the stator of the
electrical rotating machine in accordance with the third embodiment;

[0064]FIG. 19 is an illustration showing a position relationship, at the
time of fixing, between the outer circumferential edge of the stator and
the inner circumferential surface of the housing in the electrical
rotating machine in accordance with the third embodiment;

[0065]FIG. 20 is a perspective view of one rotor of the electrical
rotating machine in accordance with the third embodiment;

[0066]FIG. 21 is a partial cross-sectional perspective view of an
electrical rotating machine in accordance with a fifth embodiment;

[0067]FIG. 22 is an exploded perspective view where component elements of
the electrical rotating machine related to the fifth embodiment, are
spread out along the rotor axis direction;

[0068]FIGS. 23A and 23B are illustrations of a method for holding magnets
of an intermediate rotor of the electrical rotating machine in accordance
with the fifth embodiment, wherein FIG. 23A are exploded perspective
views and FIG. 238 is an assembly perspective view;

[0069]FIGS. 24A and 24B illustrate a first modified example of the method
for holding the magnets of the intermediate rotor of the electrical
rotating machine in accordance with the fifth embodiment, wherein FIG.
24A is a spread perspective view and FIG. 24B is an assembly perspective
view; and

[0070]FIGS. 25A and 25B are illustrations of a second modified example of
the method for holding the magnets of the intermediate rotor of the
electrical rotating machine in accordance with the fifth embodiment,
wherein FIG. 25A is a partial cross-sectional perspective view of the
intermediate rotor and a perspective view of permanent magnets thereof,
and FIG. 25B is an illustration of a position relationship, at the time
of fixing, between the rotor disc and the permanent magnet at the portion
A and portion B.

[0071]In the description, the same reference symbol is given to each same
or virtually same component element.

DETAILED DESCRIPTION OF THE INVENTION

[0072]Embodiments in accordance with the invention will be described
below, referring to the drawings.

First Embodiment

[0073]An embodiment in accordance with the invention will be described
below, referring to FIGS. 1A to 6.

[0074]FIG. 1A shows an entire view of an amorphous core 102 in a first
embodiment in accordance with the invention.

[0075]A core portion 104 of the amorphous core 102 is formed using
amorphous metal (non-crystalline metal) elements 110 in a ribbon form
(foil band) as an iron base to be in a laminated structure with
sandwiched insulation resin material elements (hereinafter, referred to
as resin) 112, wherein the amorphous metal elements 110 in the ribbon
form are respectively bonded by the resin.

[0076]The core portion 104 is in a fan shape when viewed from the top or
bottom.

[0077]Gap surfaces 106 at the top and bottom of the core portion 104 are
provided with respective resin portions 108 being layers with an
extremely thin thickness of mm so that the gap surfaces 106 are prevented
from rusting. Further, the faces at the root side and the outer side of
the fan shape of the core portion 104 are provided with layers of
respective resin portions 108 to be prevented from rusting.

[0078]In order to arrange a later-described winding wire around the
amorphous core 102, the contact portions between the winding wire and the
amorphous core 102, in other words, the edge portions of the amorphous
core 102 are provided with an edge roundness of R.

[0079]FIG. 1B shows a cross-section of the above-described amorphous
armature core, shown in FIG. 1A, the cross-section being parallel to the
gap surfaces.

[0081]A manufacturing method of the amorphous core 102 will be described
below.

<1: Iron Mold Forming Process>

[0082]FIG. 2 shows a mold for mold forming of a core. The mold has a top
cover 202, bottom cover 204, center core 242, and outer core 244. The top
and bottom covers 202 and 204 are provided with holes 206 for injecting
resin and protrusions 208 for forming grooves of the gap-surfaces. The
center core 242 is provided with protrusions 210 for forming the
recessions of the tape faces of the cores, and the outer core 244 is also
provided with protrusions (not shown) on the inner side thereof. In the
present embodiment, a protrusion 208 with a width of 2 degrees is
arranged for every 24 degrees, and accordingly, grooves in a recessed
shape with the width of 22 degrees for each are formed on the mold.
Further, protrusions 208 are preferably formed in the entire circular
range from 0 degree to 360 degrees. The amount of resin injected from the
holes 206 can be controlled, and thereby a thin and uniform thin film can
be formed. Accordingly, extremely thin resin layers with a thickness of
0.3 mm-0.5 mm are arranged on the gap surfaces 106 sides of the core
portion 104, and thus the gap surfaces 106 can be prevented from rusting.

[0083]The grooves of the mold in the recessed shape are formed by the
protrusions 208 as cut portions, so that armature cores have a structure,
where the surfaces of the amorphous winding core 120 are exposed.

[0084]The mold preferably has a circular or substantially circular shape.
As the bonding method for the ribbon formed amorphous metal elements 110,
a bonding method by an adhesive agent, welding or the like can also be
applied.

[0085]An amorphous winding core 120, as shown in FIG. 3, is set in dies,
then the dies are closed, and resin is injected from the holes 206. Then,
vacuum impregnation is performed, and thus a large amount of resin is
impregnated in the gaps between the ribbon-form amorphous winding core
120 and the mold, as shown in FIG. 4, and thus the mechanical strength at
the time of cutting the grooves 130 of the amorphous core portion 122
with resin can be ensured.

[0086]That is, there is provided an armature core 102 used for an
electrical rotating machine, wherein the armature core has a core portion
104 with lamination of a plurality of non-crystalline metal foil bands
110 and resin elements 112 for bonding the non-crystalline metal foil
bands 110, and at least two cut surfaces CS with respect to the laminated
surfaces LP. Further, the cut surfaces CS are perpendicular to the
laminated surfaces LP of the non-crystalline metal foil bands.

[0087]Further, the gap side resin portions of the armature core to be used
for a motor are arranged such as to have thickness t of 0.3 mm-0.5 mm.

[0089]FIGS. 4 and 5 show a cutting process for core portions 122 attached
with resin. Cutting of the core surfaces is performed in cooling water,
starting with the grooves 130 where the core surfaces are exposed, and
thus molds 140 are formed. The core portions 122 attached with resin and
the grooves 130 of the core portions, the core surfaces being exposed at
the grooves 130, can reduce the stress caused at the time of cutting and
prevent scattering of the lamination core. Further, with this method,
heating before cutting described in Patent Document 2 is unnecessary.
Still further, by arranging grooves 130, a preferable shape and
dimensions of a cut core can be formed. In order to arrange a winding
wire around the amorphous core 102, the contact portions between the
winding wire 160 and the amorphous core 102 are provided with an edge
roundness R.

Second Embodiment

[0090]FIG. 6 shows an axial gap motor using the amorphous cores 102 in the
first embodiment. The motor using amorphous cores in the present
embodiment includes a stator 304 having a plurality of amorphous cores
102 for the stator and winding wires 160 for the stator, and rotors 302,
304 having ferrite magnets 310 in a substantially rhombic shape. The two
rotors 302, 304 have a structure sandwiching the stator 304 therebetween,
and the motor in the present embodiment has nine poles of the stator and
six poles of magnets. However, the number of the poles of the armature
and the number of poles of magnets can have a combination other than
this. Further, depending on the case, it is possible to set the rotors in
the present embodiment on a fixing side, and make the stator rotatable.

[0091]FIG. 7 shows the detailed Shapes of the ferrite magnets 310,
amorphous cores 102, and winding wire 160. FIG. 7 shows the shape of the
motor, in FIG. 6, viewed from the top side. In order to reduce the
cogging torque, the magnets 310 are provided with skews with a certain
angle in the circular direction CIR (circumferential direction) and
radial direction RD. With regard to the magnetic poles of the magnets
310, when the rotation direction ROD is specified, N poles are arranged
in the forward direction, and S poles are arranged in the reverse
direction. Further, the winding wire 160 is wound around the amorphous
core 102 along the faces perpendicular to the motor axis. Incidentally,
by controlling a flowing current, the motor in the present embodiment can
be rotated in either direction.

[0092]Still further, as she shape of magnets 310 shown in FIG. 7, the
magnets 310 have an angle θ1: 25° with respect to the center
line, and angles θ2: 65°, θ3: 115°, θ4:
109°, and θ5: 71° as angles at the respective apexes
of the member.

[0093]These winding wires 160 of the motor are connected with a power
converter (not shown), and a power is supplied from the power converter
and controlled so that rotation of the motor rotates at a required
rotation speed.

[0094]FIG. 8 shows the waveform of the cogging torque in an embodiment of
a motor, in accordance with the invention, with magnets in a
substantially rhombic skewed shape. Further, FIG. 9 shows the waveform of
the cogging torque of a motor using conventional full-circular magnets
for the rotors.

[0095]From these test results, as compared with the conventional waveform
of cogging torque, the cogging torque in this embodiment of a motor in
accordance with the invention is low. This shows that the cogging torque
can be reduced by forming the magnets 310 in a substantially skewed shape
to be different from the shape of the stator 304 (amorphous cores 102 and
winding wirings 160), as has been described in the present embodiment.

[0096]FIG. 10 shows the detailed shape of the magnets, and FIG. 11 shows
the detailed shape of the amorphous cores.

[0097]With the motor in the present embodiment in accordance with the
invention, with regard to the skewed shape of the magnets 310 and
representing the circular length of the magnets 310 by L1 and the
circular length of the amorphous cores 102 by L2, the relationship of the
ratio L2/L1 is set to be in a range 0.4-0.53, thereby the cogging torque
being reduced.

[0098]Although, in the foregoing embodiment, structure where amorphous
metal elements in a ribbon shape are bonded primarily by resin has been
described, it is also possible, not by this bonding method, to form an
entire amorphous core by connecting the amorphous metal elements in the
ribbon shape between layers, using a bonding method by an adhesive agent,
welding or the like.

[0099]Further, because amorphous cut cores are used in the foregoing
embodiment, a motor with a low eddy current loss and a high efficiency is
realized. Still further, as it is made possible to use ferrite magnets,
reduction in the cost of a motor is realized.

[0100]Next, another embodiment in accordance with the invention will be
described in detail, referring to FIGS. 12 to 20.

Third Embodiment

[0101]FIG. 12 is a partial cross-sectional perspective view of an
electrical rotating machine in accordance with a third embodiment. FIG.
13 is an exploded perspective view where component elements of the
electrical rotating machine in accordance with the third embodiment are
spread out in the rotor axis direction. FIGS. 14A and 14B are structural
views of a core holding member of a stator of the electrical rotating
machine in accordance with the third embodiment, wherein FIG. 14A is a
perspective view, and FIG. 14B is a plan view.

[0102]As shown in FIG. 12, this axial gap electrical rotating machine 501
(hereinafter, referred to merely as electrical rotating machine 501)
includes a stator 402, and a pair of rotors 403A, 403B that are disposed
facing the surfaces of the stator 402 with a certain gap, on the both
sides of the stator 402 in the axial line direction (axial direction) AX
of the rotor shaft 401. The stator 402 and rotors 404A, 403B are housed
in a housing 404. Covers 408 in a disc form having a rotor shaft hole
408a at the central portion thereof (refer to FIG. 13) cover the outer
surfaces (the top and bottom outer surfaces in FIG. 12) on the both sides
in the axial direction AX of the rotor shaft 401.

[0104]The respective rotors 403A, 403B also serve as back yokes having a
rotor shaft hole 432a (refer to FIG. 13) at the center thereof. For
example, on one side of each rotor disc 432A, 432B of electromagnetic
steel plate or the like, permanent magnets 431 are periodically and
adhesively fixed along the circumferential direction CIR with the axis
line of the rotor shaft 401 being the central axis, and fixed by a key or
the like, not shown, coaxially with the rotor shaft 401 that outputs
rotational drive force.

[0105]The number of the permanent magnets 431 bonded to the rotor 403A,
403B is six, for example as shown in FIG. 13, and is not necessarily
required to be the number of, pole members (for example, nine) formed by
the stator core 422 and a pair of coils 423 sandwiching the core holding
member (stator core holding member) 421 of the stator 402. Further, the
planar shape of the permanent magnets 431 is not required to be the same
as the cross-sectional shape of the stator cores 422.

[0106]However, when viewed from either the top side or bottom side in FIG.
13 of the rotor shaft 404, the permanent magnets 431 of the rotor 403A
and the permanent magnets 431 of the rotor 4038 are necessary to be
periodically arranged at the same position in the circumferential
direction CIR and in the same shape.

[0107]The rotor 403A in FIG. 13 is shown in a perspective view from the
bottom side. The rotor 403B in FIG. 13 is shown in a perspective view
from the top side. The angles between the tangential line of the circle
having a center on the axial line of the rotor shaft 401 and the
respective lines forming the outer shape of the permanent magnets 431 at
the both ends thereof in the circumferential direction CIR are different
from each other.

[0108]For example, in FIG. 13, a case is shown where the planar shape of
the permanent magnets 431 is substantially rhombic. This is an example of
a shape that reduces the torque pulse and cogging torque.

[0109]As the rotors 403A, 403B, it is also possible to employ a cage
structure, magnetic material disc, conductive disc, rotor whose
reluctances are different depending on the circumferential position, or
the like, which do not use permanent magnets.

<Stator>

[0110]As shown in FIG. 12, in the stator 402, stator cores 422 in a bar
shape constructing pole members are arranged with the axial direction
thereof which is along the axial direction AX of the rotor shaft 401 and
periodically along the circumferential direction CIR around the central
axis on the axial line of the rotor shaft 401. A coil 423 is wound around
each stator core 422.

[0111]As shown in FIG. 13, the stator 402 has a bearing holding member 425
on the inner side with respect to the radial direction. The bearing
holding member 425 is provided with bearing holding holes 425a, 425a
(refer to FIG. 14) being cylindrical hollow with a bottom on the both
sides in the axial direction AX of the rotor shaft 401 to house and fix a
ball bearing 405 therein. A core holding member 421 (refer to FIG. 12 and
FIG. 14) substantially in a disc shape extends from the outer
circumferential surface of the bearing holding member 425 outwardly in
the radial direction.

[0112]The rotor shaft 401 has the bottom portion of the bearing holding
holes 425a, and penetrates the bottom portion through a rotor shaft hole
425b (refer to FIG. 14) such as to ensure a gap from the outer
circumferential surface of the rotor shaft 401 thereto.

[0113]Herein, both the core holding member 421 and bearing holding member
425 are made of a highly strong engineering plastic and are integrally
formed.

[0114]AS shown in FIGS. 14A and 14B, the core holding member 421 is
arranged with an annular disc basic portion region 421d extending from
the outer circumferential surface of the bearing holding member 425 to
the outer, side with respect to the radial direction, and core holding
regions 421a, 421b substantially in a fan shape which are continuous from
the outer circumferential side, with respect to the radial direction, of
the disc basic portion region 421d to the outer side with respect to the
radial direction, the core holding regions 421a, 421b being disposed
periodically along the circumferential direction CIR, for example, in the
order of 421a, 421b, 421b, 421a, 421b, . . . .

[0115]Each core holding region 421a has an edge portion (a first outer
circumferential edge portion) 421a1 on the outer side with respect
to the radial direction thereof, the edge portion 421a1 extending to
the both sides with respect to the circumferential direction CIR. Each
core holding region 421b has an edge portion (a second outer
circumferential edge portion) 421b1 on the outer side with respect
to the radial direction thereof, the edge portion 421b1 extending to
the both sides with respect to the circumferential direction CIR.

[0116]The distance of the outer side end of the edge portion 421a1,
in the radial direction thereof, from the axial line (rotational central
axis) of the rotor shaft 4'01 is set to be slightly larger than that of
the outer side end of the edge portion 421b1. Accordingly, when the
stator 402 is assembled into the housing 404, the outer circumferential
surface of each edge portion 421a1 and the inner circumferential
surface 404a (refer to FIG. 20) of the housing 404 come in contact with
each other, and a gap is formed between the outer circumferential surface
of each edge portion 421b1 and the inner circumferential surface
404a of the housing 404.

[0117]Further, between respective core holding regions 421a, 421b which
are adjacent to each other along the circumferential direction CIR, a
hole or recession 421c1 is formed in substantially the same
cross-sectional shape as that of the stator core 422, a substantial fan
shape, for example. Between respective core holding regions 421a, 421b
which are adjacent to each other along the circumferential direction CIR,
a hole or recession 421c2 is formed likewise in substantially the
same cross-sectional shape as that of the stator core 422, a substantial
fan shape, for example.

[0118]Further, notches 421e are formed between the respective ends, in the
circumferential direction CIR, of edge portions 421a1 and the ends,
in the circumferential direction CIR, of edge portions 421b1, and
between the edge portions 421b1 and edge portions 421b1 being
adjacent to each other in the circumferential direction CIR. Thus,
between adjacent core holding regions 421a and 421b, and also between
adjacent core holding regions 421b and 421b, the edge portions thereof
are cut on the outer side with respect to the radial direction thereof.

[0119]Incidentally, the holes or recessions 421c1, 421c2
substantially in a fan shape have substantially the same planar shape,
and are formed corresponding to the number of the pole members of the
stator and periodically along the circumferential direction CIR with the
axial line of the rotor shaft 401 being the central axis, for example, in
the order of 421c1, 421c1, 421c2, 421c1, 421c1,
and 42102.

[0120]Incidentally, the corner portions of the circumferential edges of
the holes or recessions 421c1, 421c2 are preferably provided
with an edge roundness to avoid stress concentration.

[0121]In FIG. 14B, the positions of the outer shapes of coils 423 are
shown with virtual lines so as to show the position relationship of the
outer shapes of the coils 423, in a state that stator cores 422 have been
insertion-fixed to the edge portions 421a1, 421b1 and in the
holes or recessions 421c1, 421c2, and then the coils 423 are
insertion-fixed to the stator cores 422.

<Stator Core>

[0122]Now, arrangement of a stator core 422 will be described, referring
to FIG. 15. As the material for a stator core 422, a soft magnetic
material, such as silicon steel plate, amorphous, powder magnetic core,
permalloy, or permendur, can be employed. In a case of using thin plates
of silicon steel plates, permalloy, or the like, a winding core 422'
prepared as shown in FIG. 15A is subjected to annealing for distortion
elimination, and bonded by resin, adhesive agent or the like, and cut
into a predetermined shape, as shown in FIG. 15B, to be arranged as a
stator core 422A (in FIG. 12, FIG. 13, and later-described FIGS. 16, 18,
and 20, representatively shown as stator core 422).

[0123]Further, also in a case of using a foil band, such as amorphous, a
core having a cross-sectional shape substantially in a fan shape can be
obtained by a similar method.

[0124]Incidentally, in a case of using foil bands, such as amorphous,
instead of cutting out from the shape of the winding core 422' shown in
FIG. 15A, a core can be formed by directly winding foil bands, such as
amorphous, such that the cross-section becomes a fan shape.

[0125]A stator core 422B of a powder magnetic core formed by powder
compacting of magnetic powders coated with resin can be directly formed
into a shape as shown in FIG. 15C. Further, it is also possible to make
the stator core 422B anisotropic through forming such that the magnetic
properties are excellent along the axial direction shown by the arrow.
When a stator core 422 is formed of a powder magnetic core, because the
cross-section with respect to the axial direction can be formed into any
shape, it is possible to form the stator core into a shape with an edge
roundness at edge portions like the stator core 422C shown in FIG. 15D.

[0126]When a stator core 422 is formed from plates, a press-lamination
method can be considered instead of the above. In this case, if a
cross-sectional shape of a substantial rectangle, as shown in FIG. 15E,
instead of a fan shape is applied, stator cores 422D can be manufactured
also by such a method.

[0127]The cross-sectional shape of a stator core 422 is not limited to the
above-described substantial fan shape or rectangle, and can be a circular
shape or ellipse.

[0128]Next, referring to FIGS. 16 to 20, and FIGS. 13 and 14 as necessary,
an assembling method of the stator 402 and an assembling method of the
electrical rotating machine 501 will be described.

<Fitting of Core Holding Member to Stator Core>

[0129]FIG. 16 is a perspective view taken after the stator cores have been
fixed to the core holding member of the stator.

[0130]As shown in FIG. 16, first, the stator cores 422 are press-inserted
and fixed to the holes or recessions 421c1, 421c2 (refer to
FIG. 14B) formed on the core holding member 421. That is, for example,
the core holding member 421 is fixed on a jig table having a certain
number of receiving holes with a depth for inserting the stator cores 422
into the holes or recessions 421c1, 421c2 from one side and
protruding the stator cores 422 to the opposite side, and the stator
cores 422 are press-inserted sequentially one by one from the one side.
Thus, the central portions, around the axial direction, of the stator
cores 422 can be easily fixed and held by the core holding member 421.
Herein, formation of the notches 421e allows the core holding regions
421a, 421b to move along the circumferential direction CIR at the time of
press-inserting, and thereby cracking of the holes or recessions
421c1, 421c2 is prevented. Further, the corners of the edges of
the holes or recessions 421c1, 421c2 are given with edge
roundness as described above, and thereby cracking at the corner portions
upon press-insertion of the stator cores 422 can be prevented.

<Fitting of Coils to Stator Cores>

[0131]FIG. 17 is an illustration of a method for fitting coils to stator
cores. FIG. 18 is an entire perspective view of the stator of the
electrical rotating machine in accordance with the third embodiment.

[0132]Coils 423, 423 are connected with each other through the winding
wire intermediate portion 423a to be arranged as coils of one pole
component. This coil manufacturing method can be a method of assembling
coils wound around insulating bobbins, a method of direct winding of
wires around the stator cores 422, or the like. Herein, because
connecting at the winding wire intermediate portion 423a of coils would
require a complicated manufacturing process if carried out in a later
process, it is preferable that winding of two coils 423, 423 disposed
along the axial direction of the stator cores 422 are continuously
carried out in advance, and the winding wire intermediate portion 423a is
provided, for which assembly is carried out from the both sides along the
axial direction. Further, a method can be considered for streamlining of
wiring where coils 423 are connected continuously from the winding wire
ends 423b, 423b, and coils in the same phase are continuously wound for
assembling a 3-phase electrical rotating machine. By a procedure as
described above, the stator 402 of the electrical rotating machine 501
can be obtained.

[0133]Concrete description will be made below, taking an example.
Similarly to the connection, as shown in FIG. 17, of two coils 423 at the
winding wire intermediate portion 423a, using two insulating bobbins (not
shown) with the same cross-sectional shape of the stator cores 422, coils
423 for one pole member are formed. Then, as shown in FIG. 18, coils 423,
423 for one stator core 422 are inserted from the both sides of the core
holding member 421. Herein, wire winding direction is set to be the same
around the axis line direction AX of the rotor shaft 401 in assembling.
Then, the coils 423 are impregnated with resin or the like to bond the
coils 423 to the stator core 422.

[0134]Incidentally, the wiring ends 423b, 423b may be connected with coils
423 for other pole components in the same phase.

[0135]The winding wire intermediate portion 423a and winding wire ends
423b are bonded to the core holding regions 421a, 421b of the stator 402
with resin or the like so as not to contact the rotors 403A, 4038.

<Fitting of Stator to Housing>

[0136]Next, a method for fixing the stator 402 to the housing 404 will be
described, referring to FIG. 19.

[0137]FIG. 19 is an illustration showing a position relationship, at the
time of fixing, between the outer circumferential edge of the stator and
the inner circumferential surface of the housing in the electrical
rotating machine in accordance with the third embodiment.

[0138]As shown in FIG. 19, the stator 402 is press-inserted into the
housing 404 in a cylindrical shape so that the stator 402 and housing 404
can be fixed to each other. As described above, only the edge portions of
the core holding regions 421a in a fan shape of the core holding member
421 come in contact with the inner circumferential surface 404a of the
housing 404 and thus fixed.

[0139]Incidentally, although not shown in FIG. 19, a ball bearing 405 is
already insertion-fixed to the bearing hole 425b on the upper side in
FIG. 19.

<Assembly of Stator and Rotors>

[0140]FIG. 20 is a perspective view of one rotor of the electrical
rotating machine in accordance with the third embodiment.

[0141]Referring to FIG. 13 and FIG. 20, an assembly procedure of the
rotors 403A, 403B to the stator 2 will be described.

[0142]First, as shown in FIG. 20, the rotor shaft 401 is inserted into the
rotor shaft hole 432a of the rotor 403B from one side with respect to the
axial line direction AX, and then fixed integrally with the rotor shaft
401 by a key or the like. Next, in FIG. 20, a ball bearing 405 fitted to
the rotor shaft 401 on the upper side of the rotor 403B. Then, in FIG.
13, the rotor shaft 401 is inserted from the lower side into the rotor
shaft hole 425b of the stator 402 already fixed to the housing 404, and
the ball bearing 405 fitted around the rotor shaft 401 is fitted into the
bearing holding hole 425a on the lower side of the stator 402. Herein,
the rotor disc 4323 held at a position on the lower end side of the
bearing holding member 425 is in a position relationship such as to have
a gap dimension designed in advance between the permanent magnets 431 and
the facing surfaces of the stator cores 422.

[0143]The rotor shaft 401 is in a state of projecting to the upper side of
the stator 402 in FIG. 13. On this upper side, a ball bearing 405 is
fitted into the bearing holding hole 425a on the upper side of the stator
402, and the rotor shaft 401 is penetrated through the rotor axis hole
432a of the rotor disc 432A. Thus, assembly is carried out with a
position relationship for the position in the axial line direction AX to
have a gap dimension designed in advance. Herein, the rotor disc 432A
held at a position on the upper end side of the bearing holding member
425 is in a position relationship such as to cause a gap dimension
designed in advance between the permanent magnets 431 and the facing
surfaces of the stator cores 422.

[0144]Finally, the upper and lower covers 408 in FIG. 13 are fitted to the
housing by a method of adhesive bonding or the like.

[0145]Incidentally, a circuit board for 3-phase power to be supplied to
the respective pole components of the stator 2 may be arranged inside one
of the covers 408.

[0146]The electrical rotating machine 501 in the present embodiment is
shown such that the rotor shaft 401 is a straight shaft and is fixed by
press-insertion to the inner rings of the ball bearings 405 and the rotor
shaft holes 432a, 432a of the rotor discs 432A, 4326. However,
practically, by employing a stepped shaft, the dimension relationship
along the axial direction can be maintained with high accuracy. Because
the bearing holding member 425 and core holding member 421 are arranged
to be firmly fixed to the housing 404, a structure capable of obtaining
rotation output from the rotor shaft 401 (output shaft) is realized with
a structure externally fixing the housing 404.

Modification of Third Embodiment

[0147]Incidentally, in the present embodiment, the outer side, with
respect to the radial direction, of the disc basic portion region 421d
(refer to FIG. 14) of the core holding member 421 divided along the
circumferential direction CIR by the core holding regions 421a, 421b,
however, without being limited thereto, the outer side, with respect to
the radial direction, of the disc basic portion region 421d may have a
mere shape of an annular disc region formed with holes or recessions
421c1, 421c2 substantially in a fan shape. In this case, it is
unnecessary to provide notches 421e, and a shape whose outer
circumferential portion is partially extending outward in a certain
amount may be applied.

[0148]According to the present embodiment and the modification thereof,
because the core holding member 421 is made of engineering plastic, an
eddy current due to the rotation of the rotors 403A, 403B is not caused
in the core holding member 421, which realizes an electrical rotating
machine with little iron loss and with high efficiency.

Fourth Embodiment

[0149]Now, a fourth embodiment in accordance with the invention will be
described, referring to FIGS. 12 to 20.

[0150]In the third embodiment, the core holding member 421 and bearing
holding member 425 are made of a highly strong engineering plastic and
integrally formed, however, the invention is not limited thereto.

[0151]In the present embodiment, a core holding member 421 and bearing
holding member 425 are individually manufactured. Herein, the core
holding member 421: is made of, for example, a metallic material with
high strength, such as an aluminum alloy or steel plates; is provided at
the central portion thereof with a circular hole for inserting the
bearing holding member 425 of steel substantially in a cylindrical shape;
and is substantially in a disc shape formed with holes or recessions
421c1, 421c2 with, for example, substantially in a fan shape,
the holes or recessions being substantially in the same shape as the
cross-sectional shape of the stator cores 422, as shown in FIG. 14, in
the third embodiment. The bearing holding member 425 is fittingly fixed
into the hole at the above-described central portion of the core holding
member 421 by a method, such as press-insertion, shrink fitting, gap
fitting, or the like.

[0152]Incidentally, the bearing holding member 425 has the same shape as
in the third embodiment.

[0153]Further, before the stator cores 422 are fittingly fixed into the
holes or recessions 421c1, 421c2, at least either the edge
portions of the holes or recessions 421c1, 421c2, or the side
faces of the stator cores 422, are subjected to coating for electrical
insulation. Thereafter, the stator cores 422 are subjected to a method,
such as press-inserting, shrink fitting; or gap-fitting, so that the
central portions, around the axial direction, of the stator cores 422 are
fixed to the core holding member 421.

[0154]As coating for electrical insulation, coating by a non-conductive
material, such as ceramic or resin, is more suitable than mere painting
because of resistance against peeling-off by press-fitting and the like.
If painting is adopted, baking/painting is preferable.

[0155]The distance of the outer end, with respect to the radial direction,
of a edge portion 421a1 from the axial line (rotational central
axis) of the rotor shaft 401 is set to a little larger than that of the
outer end, with respect to the radial direction, of a edge portion
421b1. Accordingly, when the stator 402 is assembled to the housing
404, the outer circumferential surface of each edge portion 421a1
and the inner circumferential surface 404a (refer to FIG. 20) of the
housing 404 come in contact with each other, and a gap is formed between
the outer circumferential surface of each edge portion 421b1 and the
inner circumferential surface 404a of the housing 404.

[0156]Further, similarly to the description in the third embodiment with
reference to FIG. 14, there are formed respective notches 421e between
the end, with respect to the circumferential direction CIR, of each edge
portion 421a1, and the end, with respect to the circumferential
direction, of a edge portion 421b1, the edge portion 421a1 and
edge portion 421b1 being adjacent to each other with respect to the
circumferential direction CIR. Further, there are formed respective
notches 421e between the end, with respect to the circumferential
direction, of each edge portion 421b1, and the end, with respect to
the circumferential direction, of a edge portion 421b1, the edge
portions 421b1 being adjacent to each other with respect to the
circumferential direction CIR. Thus, between adjacent core holding
regions 421a, 421b, and also between adjacent core holding regions 421b,
421b, the edge portions thereof are cut on the outer side with respect to
the radial direction thereof.

[0157]In assembling the stator 402 (refer to FIG. 12) in the present
embodiment into the housing 404, the stator 402 is subjected to a method,
such as shrink fitting, press-insertion, gap-fitting, or the like, along
the axial direction AX of the rotor shaft 401, and thereby the housing
404 and the stator 402 can be fixed to each other. Herein, the core
holding member 421 withstands the stress due to press-insertion or shrink
fitting, because a material with a sufficient strength is used for the
core holding member 421.

[0158]Further, when the stator 402 is assembled into the housing 404, the
outer circumferential surface of each edge portion 421a1 and the
inner circumferential surface 404a (refer to FIG. 20) of the housing 404
come in contact with each other, while a gap is formed between the outer
circumferential surface of each edge portion 421b1 and the inner
circumferential surface 404a of the housing 404. Accordingly, although
eddy current is caused in the core holding member 421 by a magnetic flux
flowing through the stator cores 422 of the electrical rotating machine
501, along a direction interfering with the flux, a current path flowing
around the stator cores 422 can be cut off even when the housing 404 is
made of a conductive material, such as steel plates, or aluminum alloy.
Needless to say, when the housing 404 is made of a conductive material,
such as steel plate or aluminum alloy, it is desirable that at least
either the outer circumferential surface of each edge portion 421a1
or the inner circumferential surface 404a of the housing 404 is coated
for electrical insulation as described above.

[0159]Further, because at least either the side faces of the stator cores
422 or the edge portions of the holes or recessions 421c1,
421c2 are coated for electrical insulation, it is possible to reduce
generation of eddy current loss caused by electrical conduction between
the edge portions of the holes or recessions 421c1, 421c2 of
the core holding member 421 holding the stator cores 422, and the stator
cores 422.

[0160]In accordance with the present embodiment, because the bearing
holding member 425 and the core holding member 421 are firmly fixed to
the housing 404, a higher rotation output from the rotor haft 401 (output
shaft) than in the case of the third embodiment can be obtained, with a
structure that externally fixes the housing 404.

Fifth Embodiment

[0161]Now, an electrical rotating machine in accordance with a fifth
embodiment will be described, referring to FIGS. 21 to 25.

[0162]FIG. 21 is a partial cross-sectional perspective view of the
electrical rotating machine in accordance with the fifth embodiment, and
FIG. 22 is an exploded perspective view where component elements of the
electrical rotating machine in accordance with the fifth embodiment are
spread out along the direction of the rotor shaft.

[0163]As shown in FIG. 21, for this axial gap electrical rotating machine
505 (hereinafter, referred to merely as electrical rotating machine 505),
stators 402 in the above-described third or fourth embodiment are housed
in a housing 404 along the axial line direction AX of a rotor shaft 41 in
two layers. A rotor 408A in the above-described embodiment 3 is arranged
on the upper side of the stator 402 at the upper step in FIG. 21; a rotor
403C being an intermediate rotor is arranged between two layers of the
stators 402. A rotor 403B in the above-described third embodiment is
arranged on the lower side of the stator 402 at the lower step in FIG.
21. The outer faces (the upper and lower faces in FIG. 21) on the both
sides in the axial line direction AX of the rotor shaft 401, are covered
by disc shaped covers 408 having a rotor shaft hole 408a at the central
portion thereof (refer to FIG. 22).

[0165]Incidentally, in the third and fourth embodiments, ball bearings
405, 405 are fitted in the respective bearing holding holes 425a, 425a
(refer to FIGS. 12 and 14) of the bearing holding member 425 of the
stator 402, on the both sides with respect to the axial direction AX of
the rotor shaft 401. However, the present embodiment is different from
the third and fourth embodiments in that, in FIG. 21, a ball bearing 405
is fitted in the upper side bearing holding hole 425a of a bearing
holding member 425 of the stator 402 at the upper step, while a ball
bearing 405 is fitted in the lower side bearing holding hole 425a of a
bearing holding member 425 of the stator 402 at the lower step.

[0166]The same reference symbols will be given to the same elements as
those in the third or fourth embodiment, and overlapping description will
be omitted.

<Intermediate Rotor>

[0167]Next, referring to FIGS. 23A and 23B, the rotor 403C to be the
intermediate rotor being a feature of the present embodiment will be
described. FIGS. 23A and 23B are illustrations of a method of holding the
magnets of the intermediate rotor of the electrical rotating machine in
accordance with the fifth embodiment, wherein FIG. 23A is an exploded
perspective view, and FIG. 238 is an assembly perspective view.

[0168]The rotors 403A, 403B have a structure where the rotor discs 432A,
432B thereof form respective back yokes for the permanent magnets 431,
while the rotor 403C has a structure where the rotor disc (field magnetic
pole holding member) 432C thereof does not form a back yoke for the
permanent magnets 431. That is, the rotor disc 432C is preferably made of
a non-magnetic body or non-conductive material, and has, for example, a
structure substantially in a disc shape of an engineering plastic with a
high strength. The rotor disc 432C has a rotor shaft hole 432a at the
center thereof and holding holes (magnet holding holes) 432b for holding
the permanent magnets 431 with the same periodicity as the disposition of
the permanent magnets 431 of the rotors 403A, 403B and the same shape.
The permanent magnets 431 are adhesively fixed to the holding holes 432b.
Thus, the permanent magnets 431 of the rotor 403C are correctly disposed
in the rotor disc 432C, as shown in FIG. 233, which enables arrangement
of a rotor capable of effectively using the faces, on the both sides in
the axial line direction AX, of the rotor shaft 401.

[0169]Incidentally, in FIG. 22, a permanent magnet 431 of the rotor 403A,
permanent magnets 431 of the rotor 403C, and a permanent magnet 431 of
the rotor 403B, the permanent magnets being disposed at the same position
with respect to the circumferential direction CIR, are arranged such that
the magnetic polarities facing the stators 402 are in the order, for
example, of N pole (rotor 403A), S pole (the upper face of the rotor 403C
in FIG. 22), N pole (the lower face of the rotor 403C in FIG. 22), and S
pole (rotor 403B) from the top, or in the order of S pole (rotor 403A), N
pole (the upper face of the rotor 403C in FIG. 22), pole (the lower face
of the rotor 403C in FIG. 22), and N pole (rotor 403B) from the top.

[0170]The electrical rotating machine 505 in the present embodiment has
four gap planes contributable to the torque output, realizing an
electrical rotating machine 505 with a high output. An axial gap
electrical rotating machine has a feature of having a flat shape with
respect to the axial line direction AX of the rotor shaft 401, and
accordingly the diameter was necessary to be large so as to obtain a
large output of the axial gap electrical rotating machine. However, in
accordance with the present embodiment, an electrical rotating machine
with a high output can be obtained by superposing stators and an
intermediate rotor along the axial line direction AX of the rotor shaft
401.

[0171]Further, regarding the method of fixing the stators 402 to the
housing 404, by varying the inner diameter of the housing 404 with steps,
the positioning accuracy along the axial line direction AX of the rotor
shaft 401 of the stators 402 at the time of fixing the stators 402 inside
the housing 404 can be improved.

[0172]Next, referring to FIG. 24, a structure of a rotor 403D to be a
first modified example, of the rotor 403C, for holding permanent magnets
431B with a similar structure to the above will be described.

[0173]FIGS. 24A and 24B are illustrations of the first modified example of
the magnet holding method for the intermediate rotor of the electrical
rotating machine in accordance with the fifth embodiment, wherein FIG.
24A is an exploded perspective view, and FIG. 24B is an assembly
perspective view.

[0174]The rotor 403C includes a pair of rotor disc halves (field magnetic
pole holding members) 433A, 433B having a rotor shaft hole 433a at the
central portion thereof, and permanent magnets 431B held by being
sandwiched therebetween. As shown in FIG. 24A, the permanent magnets 431B
have recessions 431a1, 431a2 substantially along the radial
direction on the both faces. The rotor disc halves 433A, 433B have
holding holes (magnet holding holes) 433b for holding the permanent
magnets 431B as well as the rotor 403C has the holding holes 432b (refer
to FIG. 23A), however, the rotor disc halves 433A, 433B are provided with
bridge portions 433c1, 433c2 for inhibiting moving of the
permanent magnets 431B along the axial line direction AX of the rotor
shaft 401. The bridge portions 433c1, 433c2 are disposed at
positions in the holding holes 432b, the positions corresponding to the
above-described recessions 431a1, 431a2 of the permanent
magnets 431, and on respective one sides of the rotor disc halves 433A,
433B, the one sides facing the respective stators 402 (refer to FIG. 22).
The bridge portions 433c1, 433c2 are arranged to have a smaller
thickness than that of the rotor disc halves 433A, 433B with respect to
the axial direction AX of the rotor shaft 401 so that the thickness of
the portion of the permanent magnets 431B along the axial line direction
AX of the rotor shaft 401, the portion corresponding to the position of
the bridge portions 433c1, 433c2, is not significantly
decreased. Incidentally, the two rotor disc halves 433A, 433B are
arranged such that the thickness of the rotor 403D is not larger than
that of the permanent magnets 431B.

[0175]The permanent magnets 431B are disposed between the rotor disc
halves 433A, 4338, and the rotor disc halves 433A, 433B and the permanent
magnets 431B are assembled with an adhesive agent, as shown in FIG. 24B.

[0176]The permanent magnets 4318 have the Magnetic pole surfaces exposed
through the windows 433b1, 433b2 (refer to FIG. 24A) of the
holding holes 432b to the stator 402 sides (refer to FIG. 22).

[0177]Incidentally, in FIG. 24A, the recessions 431a1, 431a2 and
the bridge portions 433c1, 433c2 are arranged substantially
along the radial direction and at the same circumferential positions,
however, the invention is not limited thereto. In order to increase the
strength of the recessions 431a1, 431a2 of the permanent
magnets 431B, the bridge portions 433c1, 433c2 may be arranged,
for example, in an X shape, and the recessions 431a1, 431a2 may
be arranged corresponding thereto.

[0178]By fixing the permanent magnets 431B to the rotor 403D as in present
modified example, the increase in the bonding area compared with the
bonded surfaces between the permanent magnets 431 of the rotor 403C and
the edge portions of the holding holes 432b, and the holding by the
bridge portions 433c1, 433c2 strengthen the function to hold
the permanent magnets 431B of the rotor 403D against the absorbing force
and repulsive force by the permanent magnets 4318 along the axial line
direction AX of the rotor shaft 401, and thereby the possibility of
separating off of the permanent magnets 431B is lowered. Further, an
intermediate rotor being thin with respect to the axial direction AX of
the rotor shaft 401 can be arranged.

[0179]Next, referring to FIGS. 25A and 25B, a structure of a rotor 403E
being a second modified example of the rotor 403C will be described,
wherein the rotor 403E holds the permanent magnets 431C with a structure
similar to the above.

[0180]FIGS. 25A and 25B are illustrations of a second modified example of
a method of holding the magnets of the intermediate rotor of the
electrical rotating machine in accordance with the fifth embodiment,
wherein FIG. 25A is a partial cross-sectional perspective view of the
intermediate rotor and a perspective view of the permanent magnets
thereof, and FIG. 25B is an illustration of a position relationship
between the portions A and B of the rotor disc, and the permanent magnets
at the time of fixing. A rotor disc (field magnetic pole holding member)
432D of the rotor 403E of the present modified example is made of a
single plate substantially in a disc shape having a rotor shaft hole 432a
at the central portion thereof, and is provided with holding holes
(magnet holding holes) 432b for holding the permanent magnets 431C with
the same periodicity as the disposition of the permanent magnets 431 of
the rotors 403A, 403B and with the same shape.

[0181]The permanent magnets 431C fitted inside the holding holes 432b are
resin molded magnets formed by insert-forming by the use of injection
molding or the like into the holding holes 432b provided through the
rotor disc 432D formed in advance. By such a forming method, the
permanent magnets 431C are, as shown in FIG. 25B which shows the portion
A and portion B in FIG. 25A, formed such that the both side portions of
the permanent magnets 431C, the both sides being with respect to the
axial line direction AX of the rotor shaft 401 and the both side portions
being at the edge portions of the planar shape of the permanent magnets
431C, sandwich the edge portions of the holding holes 432b, and the
permanent magnets 431C are thus fixed to the rotor disc 432D. The both
faces, with respect to the axial direction of the rotor shaft 401, of the
permanent magnets 431C are exposed, and the rotor disc 432D is arranged
to have a thickness smaller than that of the permanent magnets 431C.

[0182]Incidentally, as resin molded magnets, those formed by the use of a
resin composite material of ferrite and thermoplastic resin for ferrite
bonded magnets are well known.

[0183]The fixing of the permanent magnets 431C to the rotor 403E as the
present example strengthens, compared with the bonded surfaces between
the permanent magnets 431 of the rotor 403C and the edge portions of the
holding holes 432b, the function to hold the permanent magnets 431C of
the rotor 403E against the absorbing force and repulsive force by the
permanent magnets 431C along the axial line direction AX of the rotor
shaft 401 is improved, and thereby the possibility of separating off of
the permanent magnets 431C is lowered. Further, an intermediate rotor
being thinner with respect to the axial direction AX of the rotor shaft
401 can be arranged.

INDUSTRIAL APPLICABILITY

[0184]Amorphous cores in accordance with the invention can be applied to
brushless motors aimed at downsizing, high efficiency, and low noise.
Further, a motor having an axial gap structure by the use of amorphous
cores in accordance with the invention can be applied to general motor
systems, such as fan systems, with a thin shape and high efficiency.

Patent applications by Hiromitsu Itabashi, Tottori JP

Patent applications by Motoya Ito, Hitachinaka JP

Patent applications by Ryoso Masaki, Narashino JP

Patent applications by Shigeho Tanigawa, Okegawa JP

Patent applications by Yuji Enomoto, Hitachi JP

Patent applications by Zhuonan Wang, Hitachi JP

Patent applications in class With single stator and plural sets of rotating magnets

Patent applications in all subclasses With single stator and plural sets of rotating magnets